|Publication number||US4157715 A|
|Application number||US 05/886,074|
|Publication date||12 Jun 1979|
|Filing date||13 Mar 1978|
|Priority date||25 Mar 1977|
|Also published as||DE2713837B1, DE2713837C2|
|Publication number||05886074, 886074, US 4157715 A, US 4157715A, US-A-4157715, US4157715 A, US4157715A|
|Original Assignee||Erhard Westerhoff|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (4), Referenced by (85), Classifications (12)|
|External Links: USPTO, USPTO Assignment, Espacenet|
The present invention concerns an intracorporal drive for producing a continuous traction or pressure, respectively, especially for an extension unit intended for extension osteotomy or for a compression unit intended for pressure osteosynthesis, and to method of operation thereof.
Drives, for instance for an extension unit for extension osteotomy comprising two telescopically adjustable parts which, after having cut the bone, are both separately screwable to the bone to be extended and which are prevented from backward movement, are known in various constructions. German Pat. No. 2,417,233 discloses, for example, a motor drive disposed in the extension unit which is controlled by electrotechnical means. Such a drive is comparatively expensive and requires a highly specified outer covering in order to prevent any contact with the surrounding tissue. The use of a pressure gas drive, which is also described in the above mentioned German patent publication, is rather problematic, because a strong intracorporal pressure wave could be produced in case of breakage of the extension unit.
Hence, it is a primary object of the present invention to provide a drive which can be manufactured without great technical resources and which as far as possible is sealed against the surrounding tissue after implantation.
Another object of the invention is to provide a new and improved construction of drive which does not require any control mechanism after the implantation of the unit with which it is equipped.
Still a further object of the present invention concerns a novel method of operating an intracorporal drive.
According to the invention, these objects and others are fulfilled by the use of the osmotic pressure between a first solution of higher concentration and a second solution of lower concentration or a pure solvent, respectively, which solutions are separated by a semipermeable membrane or diaphragm, whereby means are provided to keep the solution of lower concentration or the pure solvent, as the case may be, in contact with the semipermeable diaphragm.
The choice of the semipermeable diaphragm depends upon the type of solutions to be separated. Principally, all types of diaphragms or membranes known for technical applications--e.g. for the reverse osmosis--can be used as far as they are toxicologically sufficiently defined and unobjectionable. Since direct contact with the organism is extensively excluded, the safeness must above all be proven by migration tests (i.e. tests about the migration of additives, as e.g. plasticizers, from the diaphragm into a solvent). As examples may be named: diaphragms based on cellulose acetate, especially cellulose acetate itself, cellulose acetate octanoate or cellulose acetate palmitate as well as diaphragms based on polyamides or cellulose polymerisates.
As solvents there can be used low-molecular or high-molecular substances which are toxicologically unobjectionable and which are, if possible, also found physiologically in the organism. This would, for example, be the case for aqueous solutions of common salt and various sugars. Since these substances can be absorbed by the body in low concentration without any harm, and since they are already contained in the blood serum, it is advantageous, especially in order to prevent any bodily harm, to use as the solution of lower concentration, i.e. as the component of the drive which delivers solvent, a physiological common salt solution, i.e. a 0.9% aqueous solution or a solution of 30 mg glucose in 100 ml water.
One of the advantages of the present invention is that because of the use of the osmotic pressure as driving means it is possible to dispense with a complicated design of the units and controls and to determine the desired extension by means of a previous determination of the amount of concentrated solution and solvent.
The magnitudes of the theoretically possible pressures and distances are given in the following calculations of the osmotic pressure of concentrated aqueous common salt solutions. The following figures related to a cross-sectional area of 1 cm2 with pure H2 O as the substance delivering solvent, are obtained for a body temperature of 37° C. and ideal solutions, i.e. without taking into account molecular forces or frictional forces, and so forth.
______________________________________ OsmoticConcentration Amount H2 O pressure/ DistanceMol NaCl/Liter H2 O cm3 bar cm______________________________________5.7 (approx. 330 g/l) approx. 15 approx. 250 approx. 164.275(approx. 250 g/l) approx. 20 approx. 195 approx. 223.42 (approx. 195 g/l) approx. 25 approx. 161 approx. 27______________________________________
It is understood for anybody skilled in the art that these values cannot be reached in practice. Due to the existing losses, the pressures and distances are considerably--at least approximately one-third--lower. It is therefore advisable to determine these values empirically for each individual case.
Furthermore, it should be mentioned that on the side of high concentration, the substance of the solution does not necessarily need to be dissolved completely. Functioning of the new drive of this development is also possible if, instead of a highly concentrated solution, there is used a saturated solution from which the substance of the solution has partly precipitated.
Moreover, the principle of making use of the osmotic pressure intracorporally can be used for various other applications in medicine and is not limited to the examples mentioned herein.
The invention will be better understood and objects other than those set forth above, will become apparent when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawings wherein:
FIG. 1 shows a top view of an extension unit for the extension osteotomy equipped with the drive according to the invention; and
FIG. 2 shows a section through the unit according to FIG. 1, taken substantially along the line II--II thereof.
Describing now the drawings, the extension unit to be driven consists of two parts 1a and 2a which are each separately fastened to the bone to be extended by means of the holes or bores 12 and 13, respectively and not particularly shown threaded bolts or other appropriate fastening expedients. The two parts 1a and 2a are telescopically adjustable after having cut the bone. The parts 1a and 2a of the unit form a piston-cylinder unit 1, 2. A backward or return movement between the piston 1 and the cylinder 2 is prevented by a well known and therefore not further described backward or return motion stop 10, 11. Between the piston 1 and the cylinder 2, there is provided a conventional sealing element, for example an O-ring, which is not shown in the drawing, made of elastic material which seals the cylinder chamber or compartment against its surroundings. The osmotic pressure generated in a concentrated solution 3' by a solvent 4 penetrating through a semipermeable diaphragm 5 is used as the drive for a relative displacement between the piston 1 and the receiving cylinder 2.
The semipermeable diaphragm or membrane 5, fabricated for instance of cellulose acetate, bears against a porous layer 6 which, in turn, is mechanically retained by a perforated bracket or support plate 7.
The diaphragm 5 separates the inner space or chamber 3 of cylinder 2 which contains the solution 3' from another chamber or cavity 8 integrated in cylinder 2. The chamber 8 is provided with a channel 14 which flow communicates with a prestressed elastic container 9 defining a chamber. The container 9 is connected by means of a clamp element 15 to inlet 16 of the chamber 8 which extends outwardly to form such channel 14.
The chamber 8 and container 9 are filled with a low concentration solution or a pure solvent. The prestressing of container 9, which also can be accomplished, instead of by the rubber-like elastic wall, for instance by means of a spring-loaded piston, ensures that diaphragm 5 is continuously moistened or imbued by the low concentrated solution or the pure solvent, as the case may be, at least during the intended duration of effect of the drive.
As already mentioned, the volumes of the chambers 8 and 9 can be used to control the distance covered by piston 1 because of the osmotic pressure and/or the duration of effect of the drive; since as soon as, due to the increasing equalization of the concentration, the osmotic pressure no longer can overcome the counteracting forces, the drive comes to standstill. This point in time is determined by the initial dilution and the amount of solvent in chambers 8 and 9.
The intensity of the initial osmotic pressure can be influenced, among other things, by the difference of the concentration in the chambers 3 and 8 and by the thickness of the diaphragm 5, whereas the feed or advance speed of piston 1 can be altered to a certain degree by varying the area or size of diaphragm 5 which is available for the penetration of the solvent, also by the thickness and/or type of diaphragm, or combinations of the foregoing factors.
Instead of using a piston mechanism to produce the feed movement, it would be conceivable to possibly use another system, for instance an elastic system while utilizing the elongation of a housing wall for the solution in chamber 3, such as by structuring the cylinder wall to be expansible or elongatable.
In the present example under discussion, there is used an aqueous solution saturated to the solubility limit with common salt as the concentrated solution in chamber 3. This solution can be easily obtained from a solution saturated at 25° C.--or another temperature below the normal body temperature--from which the liquid phase is removed. For the increased body temperature of approximately 37° C. there is then obtained an almost saturated solution.
In the same way, there can be produced other examples for a concentrated solution, e.g. a glucose or grape sugar solution which likewise is also almost saturated.
Since pure water has a toxic effect in the body, it is advantageous to use as solutions releasing solvent in the chambers 8 and 9 diluted solutions of the same substances. Advantageously, these diluted solutions are used in a manner such that they do not differ too much from the concentration of a physiological common salt solution (0.9%) or a blood sugar level (60 mg/100 ml), respectively, at the end of the effectiveness of the drive.
It is to be understood that all solutions used sterilized before they are filled into the drive.
While there are shown and described present preferred embodiments of the invention, it is to be distinctly understood that the invention is not limited thereto, but may be otherwise variously embodied and practiced within the scope of the following claims. ACCORDINGLY,
|Cited Patent||Filing date||Publication date||Applicant||Title|
|US3900025 *||24 Apr 1974||19 Aug 1975||Barnes Jr Walter P||Apparatus for distracting or compressing longitudinal bone segments|
|US3976060 *||1 Apr 1975||24 Aug 1976||Messerschmitt-Bolkow-Blohm Gmbh||Extension apparatus, especially for osteotomic surgery|
|US4096857 *||27 Dec 1976||27 Jun 1978||Messerschmitt-Boelkow-Blohm Gmbh||Telescopically adjustable surgical instrument|
|FR1239266A *||Title not available|
|Citing Patent||Filing date||Publication date||Applicant||Title|
|US4615338 *||18 Sep 1985||7 Oct 1986||Kurgansky Nauchno-Issledovatelsky Institut Experimentalnoi I Klinicheskoi Ortopedii I Travmatologii||Automatic compression-distraction apparatus|
|US4852558 *||29 Jul 1987||1 Aug 1989||Outerbridge Howard K G||Compressible bone staple|
|US4946461 *||29 Sep 1988||7 Aug 1990||Fischer William B||Tool for removing the ball of the femur|
|US5071435 *||20 Dec 1990||10 Dec 1991||Albert Fuchs||Extendible bone prosthesis|
|US5074882 *||19 Apr 1989||24 Dec 1991||Medinov Sarl||Progressive elongation centro-medullar nail|
|US5196012 *||11 Jul 1991||23 Mar 1993||Malka Jeffrey S||External compression frame rapidly stabilizing unstable pelvic fractures|
|US5236460 *||10 Oct 1991||17 Aug 1993||Midas Rex Pneumatic Tools, Inc.||Vertebral body prosthesis|
|US5350379 *||18 Feb 1993||27 Sep 1994||Genesis Orthopedics||Bone and tissue lengthening device|
|US5352227 *||3 Feb 1993||4 Oct 1994||Howmedica Inc.||Intercalary device|
|US5429638 *||12 Feb 1993||4 Jul 1995||The Cleveland Clinic Foundation||Bone transport and lengthening system|
|US5626579 *||28 Jun 1995||6 May 1997||The Cleveland Clinic Foundation||Bone transport and lengthening system|
|US5672177 *||31 Jan 1996||30 Sep 1997||The General Hospital Corporation||Implantable bone distraction device|
|US5700263 *||17 Jun 1996||23 Dec 1997||Schendel; Stephen A.||Bone distraction apparatus|
|US5720746 *||8 Nov 1995||24 Feb 1998||Soubeiran; Arnaud Andre||Device for displacing two bodies relative to each other|
|US5723013 *||6 Feb 1996||3 Mar 1998||Jbs S.A.||Spacer implant for substituting missing vertebrae|
|US6036690 *||21 Feb 1997||14 Mar 2000||De La Plaza Fernandez; Rafael||Linear expander for the progressive correction of craniofacial deformations|
|US6106525 *||21 Sep 1998||22 Aug 2000||Sachse; Hans||Fully implantable bone expansion device|
|US6328738 *||24 Nov 1999||11 Dec 2001||Loubert Suddaby||Anterior cervical fusion compression plate and screw guide|
|US6336929||5 Jul 2000||8 Jan 2002||Orthodyne, Inc.||Intramedullary skeletal distractor and method|
|US6666867 *||13 Feb 2002||23 Dec 2003||Fast Enetix, Llc||Longitudinal plate assembly having an adjustable length|
|US6689134 *||7 Mar 2002||10 Feb 2004||Third Millennium Engineering, Llc||Longitudinal plate assembly having an adjustable length|
|US6852113||14 Dec 2001||8 Feb 2005||Orthopaedic Designs, Llc||Internal osteotomy fixation device|
|US7182782||30 Sep 2003||27 Feb 2007||X-Spine Systems, Inc.||Spinal fusion system and method for fusing spinal bones|
|US7481841||30 Jun 2004||27 Jan 2009||Depuy Products, Inc.||Adjustable orthopaedic prosthesis and associated method|
|US7559951||16 Jun 2005||14 Jul 2009||Depuy Products, Inc.||Adjustable, remote-controllable orthopaedic prosthesis and associated method|
|US7575601||27 Apr 2006||18 Aug 2009||Warsaw Orthopedic, Inc.||Locking expandable implant and method|
|US7621922||23 Aug 2004||24 Nov 2009||Osteomed L.P.||Facial osteodistraction device|
|US7635364||1 Dec 2004||22 Dec 2009||Synthes Usa, Llc||Unidirectional translation system for bone fixation|
|US7641701||2 Jun 2004||5 Jan 2010||X-Spine Systems, Inc.||Spinal fusion system and method for fusing spinal bones|
|US7655028||18 Jan 2007||2 Feb 2010||X-Spine Systems, Inc.||Spinal fusion system and method for fusing spinal bones|
|US7758648||27 Apr 2006||20 Jul 2010||Warsaw Orthopedic, Inc.||Stabilized, adjustable expandable implant and method|
|US7854752||9 Aug 2004||21 Dec 2010||Theken Spine, Llc||System and method for dynamic skeletal stabilization|
|US7879096||27 Apr 2006||1 Feb 2011||Warsaw Orthopedic, Inc.||Centrally driven expandable implant|
|US7892241||22 Oct 2007||22 Feb 2011||Osteomed, L.P.||Method and system for facial osteodistraction using a cannulated device|
|US7914581||27 Apr 2006||29 Mar 2011||Warsaw Orthopedic, Inc.||Expandable implant, instrument, and method|
|US7931651||30 Mar 2007||26 Apr 2011||Wake Lake University Health Sciences||External fixation assembly and method of use|
|US7963982||16 Jul 2007||21 Jun 2011||X-Spine Systems, Inc.||Implant plate screw locking system and screw having a locking member|
|US7981157||27 Apr 2006||19 Jul 2011||Warsaw Orthopedic, Inc.||Self-contained expandable implant and method|
|US8025681||29 Mar 2007||27 Sep 2011||Theken Spine, Llc||Dynamic motion spinal stabilization system|
|US8062366||8 Jan 2007||22 Nov 2011||Warsaw Orthopedic, Inc.||Ratcheting expandable corpectomy/vertebrectomy cage|
|US8062367||12 Jan 2007||22 Nov 2011||X-Spine Systems, Inc.||Screw locking mechanism and method|
|US8142435||19 Feb 2009||27 Mar 2012||Aesculap Implant Systems, Llc||Multi-functional surgical instrument and method of use for inserting an implant between two bones|
|US8142441||16 Oct 2008||27 Mar 2012||Aesculap Implant Systems, Llc||Surgical instrument and method of use for inserting an implant between two bones|
|US8182537||30 Oct 2007||22 May 2012||Aesculap Implant Systems, Llc||Vertebral body replacement device and method for use to maintain a space between two vertebral bodies within a spine|
|US8231681||3 Jun 2011||31 Jul 2012||Warsaw Orthopedic||Self-contained expandable implant and method|
|US8268004||16 Jul 2010||18 Sep 2012||Warsaw Orthopedic, Inc.||Stabilized, adjustable expandable implant and method|
|US8282682||17 Dec 2009||9 Oct 2012||X-Spine Systems, Inc.||Fusion system and method for fusing spinal bones|
|US8328807||9 Jul 2009||11 Dec 2012||Icon Orthopaedic Concepts, Llc||Ankle arthrodesis nail and outrigger assembly|
|US8328871||9 Nov 2006||11 Dec 2012||Warsaw Orthopedic, Inc.||Expanding vertebral body implant|
|US8366779||28 Mar 2011||5 Feb 2013||Warsaw Orthopedic, Inc.||Expandable implant, instrument, and method|
|US8372152||16 Jul 2007||12 Feb 2013||X-Spine Systems, Inc.||Spinal fusion system utilizing an implant plate having at least one integral lock and ratchet lock|
|US8377016||10 Jan 2007||19 Feb 2013||Wake Forest University Health Sciences||Apparatus and method for wound treatment employing periodic sub-atmospheric pressure|
|US8388663 *||13 Sep 2007||5 Mar 2013||Stryker Spine||Dynamic cervical plate|
|US8414584||2 Nov 2010||9 Apr 2013||Icon Orthopaedic Concepts, Llc||Ankle arthrodesis nail and outrigger assembly|
|US8419801||25 Jun 2009||16 Apr 2013||DePuy Synthes Products, LLC||Adjustable, remote-controllable orthopaedic prosthesis and associated method|
|US8425608||18 Jan 2008||23 Apr 2013||Warsaw Orthopedic, Inc.||Lordotic expanding vertebral body spacer|
|US8454603||26 Apr 2011||4 Jun 2013||Wake Forest University Health Sciences||External fixation assembly and method of use|
|US8591587||18 May 2012||26 Nov 2013||Aesculap Implant Systems, Llc||Vertebral body replacement device and method for use to maintain a space between two vertebral bodies within a spine|
|US8690950||23 May 2013||8 Apr 2014||Aesculap Implant Systems, Llc||Vertebral body replacement device and method for use to maintain a space between two vertebral bodies within a spine|
|US8702719 *||6 Dec 2011||22 Apr 2014||Aesculap Implant Systems, Llc||Surgical instrument and method of use for inserting an implant between two bones|
|US8728130||8 Jun 2011||20 May 2014||X-Spine Systems, Inc.||Implant plate screw locking system and screw having a locking member|
|US8734493||14 Sep 2011||27 May 2014||X-Spine Systems, Inc.||Screw locking mechanism and method|
|US8777995 *||9 Feb 2009||15 Jul 2014||K2M, Inc.||Automatic lengthening bone fixation device|
|US8795370||7 Aug 2012||5 Aug 2014||X-Spine Systems, Inc.||Fusion system and method for fusing spinal bones|
|US8821553||19 Apr 2006||2 Sep 2014||X-Spine Systems, Inc.||Spinal fusion system utilizing an implant plate having at least one integral lock|
|US8992529 *||6 Aug 2003||31 Mar 2015||Claudius Zeiler||Implant plate, method and facility for the manufacture thereof|
|US9034046||17 Nov 2014||19 May 2015||Aesculap Implant Systems, Llc|
|US9050136||17 May 2013||9 Jun 2015||Wake Forest University Health Sciences||External fixation assembly and method of use|
|US9078706||1 Mar 2012||14 Jul 2015||X-Spine Systems, Inc.||Intervertebral fusion device utilizing multiple mobile uniaxial and bidirectional screw interface plates|
|US20040106924 *||1 Dec 2003||3 Jun 2004||Ralph James D.||Longitudinal plate assembly having an adjustable length|
|US20040122434 *||22 Aug 2003||24 Jun 2004||Argenta Louis C.||Bone treatment employing reduced pressure|
|US20040215196 *||24 Apr 2003||28 Oct 2004||Loubert Suddaby||Cervical fusion screw guide|
|US20050021033 *||6 Aug 2003||27 Jan 2005||Claudius Zeiler||Implant plate, method and facility for the manufacture thereof|
|US20050021045 *||23 Aug 2004||27 Jan 2005||Osteomed L.P.||Facial osteodistraction device|
|US20050071006 *||30 Sep 2003||31 Mar 2005||Kirschman David Louis||Spinal fusion system and method for fusing spinal bones|
|US20050071008 *||2 Jun 2004||31 Mar 2005||Kirschman David Louis||Spinal fusion system and method for fusing spinal bones|
|US20050234448 *||18 Mar 2005||20 Oct 2005||Mccarthy James||Implantable bone-lengthening device|
|US20060004459 *||30 Jun 2004||5 Jan 2006||Hazebrouck Stephen A||Adjustable orthopaedic prosthesis and associated method|
|US20090204156 *||9 Feb 2009||13 Aug 2009||K2M, Inc.||Automatic lengthening bone fixation device|
|US20120310293 *||6 Dec 2011||6 Dec 2012||Aesculap Implant Systems, Llc.||Surgical instrument and method of use for inserting an implant between two bones|
|CN100563589C||30 Nov 2005||2 Dec 2009||新特斯有限责任公司||Unidirectional translation system for bone fixation|
|DE19604246B4 *||6 Feb 1996||1 Jun 2006||Aesculap Ag & Co. Kg||Distanzhaltendes Implantat zum Ersetzen von fehlenden Wirbelknochen|
|WO1997027811A1 *||31 Jan 1997||7 Aug 1997||Gen Hospital Corp||Implantable bone distraction device|
|WO2002071962A1 *||4 Mar 2002||19 Sep 2002||Arnaud Andre Soubeiran||Device for moving one bone portion in relation to another in one direction along a given axis|
|WO2006060506A1 *||30 Nov 2005||8 Jun 2006||Hfsc Co||Unidirectional translation system for bone fixation|
|U.S. Classification||606/60, 606/63, 606/58, 606/71|
|International Classification||A61B17/00, A61B17/56, A61F5/058, A61B17/80|
|Cooperative Classification||A61B2017/00539, A61B17/8004, A61B17/8009|